The field of the invention is electrical relays, and particularly, relays for industrial control systems. Relays may be employed separately or in combination with large numbers of similar relays to form control systems for operating machine tools and other industrial equipment. Such relays are known for their reliability and long life which makes them particularly desirable for industrial applications where faults in the control system may result in expensive down time.
In addition to being reliable, such relays must be compact to facilitate mounting large numbers of them in a minimal space. These requirements necessitate the use of small but powerful electromagnet structures which will operate a large number of electrical contacts for millions of operating cycles. Such relays are illustrated in U.S. Pat. Nos. 3,251,964; 3,453,571; 3,519,967; and 3,451,018.